Photographic roll film spool



March 1, 1938. P. SCHWARZ PHOTOGRAPHIC ROLL FILM SPOOL Filed April 19, 1935 Patented Mar. 1, i933 PATENT OFFICE PHOTOGRAPHIO ROLL FILM SPOOL Philipp Schwarz, Wuppertal-Barmen. Germany Application April 19, 1935, Serial No. 17,301

Germany April 28, 1934 11 Claims.

This application has been filed in Germany on April 28, 1934, and June 30, 1934; Great Britain on October 2, 1934, and France on October 16,

Photographic roll film spools made of sheet iron and provided with two guide walls arranged within the tubular body of the spool for guiding the paper strip carrying the film are usually of two kinds. In the first kind of spools, the guide walls are made integral with the tube of the spool, and are constituted by portions of a sheet iron blank used for making the tube of the spool, the width of the blank being greater than the periphery of the tube by an amount equal to double the diameter of the tube. Making the tube of the spool and the guide walls in one piece is rather complicated and difficult. Moreover, the amount of material required is considerable and the spools are unnecessarily heavy, as the uide walls have the same thickness as ,the tube itself and moreover usually extend over the whole length of the tube.

In the second kind of spools provided with guide walls for the paper strip, the guide walls are constituted by a U-shaped sheet iron plate separate from the tube of the spool and provided in its apex portion with a slot. This U-shaped plate is inserted axially into the tube of the spool in such a manner that the slotted apex portion bears from the interior against the portion of the tube containing the outlet slot, the longitudinal edge portions of the U-shaped plate being guided alonginwardlybent edge portions of the inlet slot of the paper strip. In this second kind of spools, the guide walls can be made of thinner sheet iron than the tube itself. The

guide walls must, however, in order to be secure against axial'displacement, extend over the whole lengthof the tube so that again a considerable amount of sheet iron material must be used and the weight of the spool is unnecessarily increased. A further important drawback of this construction is the fact that the slotted apex portion of the U-shaped sheet iron plate is not guided or properly positioned with regard to the outlet slot of the tube of the spool. It can therefore happen that the guide walls move out of position to such an extent that the slot in the apex portion of the U-shaped sheet iron plate no longer registers with the slot in the tube of the spool. The paper strip cannot then be properly inserted as it strikes against either one or the other edge of the outlet slot of the tube.

The invention relates toroll film spools of the second kind, that is, roll film spools in which guide walls separate from the tube of the spool are inserted into the tube. The object of the invention is to obviate the drawbacks inherent in the known spools of this kind. This object is attained according to the invention by so constructing the U-shaped plate that the guide walls engage the outlet slot of the paper strip provided in the tube of the spool. By this construction therequired position of the guide walls relatively to the outlet slot is reliably maintained so that the paper strip cannot strike against the edges of the outlet slot but can pass without hindrance through the two slots of the tube. At the same time, the guide walls are effectively secured against displacement in the axial direction. Therefore, they need not extend over the whole length of the tube, but it is sufiicient for them to extend only over the length of the slot, that is, the length of the comparatively short outlet slot of the tube, whereby economy of material is effected and the weight of the spool is reduced.

The accompanying drawing shows several constructional examples of the invention, for the sake of simplicity only the tubular portion of the spool and the guide walls being shown, whilst the end discs or flanges of the spool, which may be constructed and attached in any desired manner, are entirely omitted.

Fig. 1 is a cross section through the first construction on line l-l of Fig. 2.

Fig. 2 is a sectional elevation on line 2-2 of Fig. 1. I

Fig. 3 a plan of the tube,

Fig. 4 a perspective view of the guide piece alone,

Fig. 5 a cross section through the second construction on line 55 of Fig. 8,

Fig. 6 a cross section on line 66 of Fig. 8,

Fig. '7 a cross section on line of Fig. 8,

v Fig. 8 a sectional elevation on line 88 of Fig. 5,

Fig. 9 a longitudinal section on line 9-9 of Fig.

Fig. 10 a section similar to that 9 without the guide walls,

Fig. 11 a plan of the tube,

Fig. 12 the U-shaped guide member containing the guide wall in elevation.

Figs. 13 and 14 show in section a third and fourth construction.

In the figures a, a. a" and a' designate a tube made, for instance, by rolling from a sheet iron plate, and constituting the tubular core of the spool. To this tube are fixed at the ends, spool ends or flanges likewise made of sheet iron,

shown in Fig.

but not shown in the drawing. The spool, tube a, a, a" and a' is provided at two diametrically opposite points with slots b, b, b", b' and c, c, c", usually of different lengths for the passage and securing of one end of a paper strip carrying the film. In order to guide the end of the paper strip within the tube, there are provided two guide walls d, d, d and 11" made of sheet iron which traverse the interior of the tube.

In the construction according to Figs. 1 to 3, the two guide walls are constituted by the two limbs or sides of a substantially U-shaped plate at, d, f, the apex, or middle portion f of whichis provided with a longitudinal slot q serving for the passage of the paper strip. The Uashaped sheet iron plate engages with its apex or middle portion f the outlet slot 0 provided in the tube so that the guide walls d, d constituted by the limbs extend into the outlet slot 0. The free ends 72. of the two limbs d of the sheet iron plate are outwardly bent and preferably circularly curved. The U-shaped sheet iron plate rests with the outwardly bent ends 71. upon the halfoi the tube containing the inlet slot b, whereby the ends of the guide walls d adjacent to the inlet slot are secured against lateral displacement, so that they will always remain exactly symmetrical with regard to the inlet slot b. The guide walls d constituted bythe limbs of the U-shaped sheet iron plate, diverge somewhat towards the inlet slot b and preferably so that the clearance between the wall portions adjacent to the inlet slot b is somewhat greater than the clearance of the inlet slot. The U-shaped plate is inserted axially into the tube a, the bent limb ends it being during this operation somewhat pressed towards each other by hand or otherwise. When, the plate has reached the position in which the apex portion 1 registers with the outlet slot c the bent ends h of the limbs return owing to their resiliency to their initial position and at the same time the apex portion 1 is forced into the outlet slot 0. The plate is then firmly held in the tube so that it cannot move axially or oscillate, and consequently the guide walls are firmly and accurately held in the required position in the tube. If desired, the'engagement of the apex portion f with the slot 0 can be limited in a simple manner by making the limbs by reces'sing the limbs close to the apex portion j, whereby shoulders or bearing surfaces i are formed which rest against the transverse edges of the slot 0 in the tube of the spool (see Figs. 2 and 3). Moreover, the edge portions of the inlet slot 1) may, if desired, be bent inwardly, in order to bridge the space between this slot and the guide walls, as indicated at y in Fig. 1.

The longitudinal edges of the outlet slot 0 with whichthe guide walls or the apex portion of the U-shaped sheet iron plate constituting the guide walls engage, may if required be bent inwardly, or they may be rolled inwardly to constitute beaded portions, for the purpose of providing a wider guide surface for the U-shaped sheet iron plate. Moreover, the transverse edges of the outlet slot 0 may be inwardly bent.

The constructions according to Figs. 5 to 12 diii'er from the first constructions by the manner of fixing the U-shaped sheet iron plate in the tube of the spool, the characteristic feature of this construction being the fact that the sheet iron plate is fixed to the edges of the slot in the tube of the spool.

In the construction according to Figs. 5 to 12, the U-shaped sheet iron plate d, d, f, constituting the guide walls is fixed on the one hand by the transverse edges of the apex portion 1" against tongues or teeth 0 formed at the transverse edges of the outlet slot c" provided in the tube, and on the other hand by the edge portion w of the limbs d, d being somewhat bent outwardly and engaging below the ends of the longitudinal edges of the slot 0'. In order to enable these portions to be bentoutwardly to engage under the ends of the longitudinal edges of the slot c, small slots or cuts a: areformed upon the edge portions of the plate limbs close to the apex portion f parallel to the wall or the tube, as shown in Fig. 12. In this construction, the U-shaped sheet iron plate can, after the completion of the spool, be inserted into the tube, by compressing the limbs d, d' and inserting them with their free ends forward into the delivery slot 0'. As soon as the transverse edges of the middle or apex portion I rest upon the tongues v, the limbs d move apart so that their edge portions w engage below the longitudinal edges of the slots 0'. In order to facilitate insertion of the U-shaped guide member, the edges 01 each of the plate limbs d, d may be constructed to converge towards the free ends, either as shown in Figs. 8 and 12 upon a portion 10 of the length, or upon their whole lengths. To insurethat the middle portion 1" of the member d, d, I should lie flush with the side of the tube, the tongues or teeth 1; provided at the small edges of the slot can be bent inwardly at an angle.

The tongues may, however, be bent first at an being then omitted. In this modified construction, small recesses for receiving the tongues of the guide member d, d, ,f' are advantageously provided at the transverse edges of the slot 0' in the wall of the tube of the spool, in order that theapex portion ,f' of the guide member should lie exactly flush with the wall of the tube.

In the construction according to Fig. 13, the U-shaped guide member d, d", f" is fixed along the longitudinal edges of the delivery slot 0''. For this purpose the two limbs d", d" of the guide member are provided in the vicinity of the apex portion 1" each with two projections or bulges, m, n formed by folds or creases, said projections engaging the longitudinal edges of the slot c". The guide member is again inserted through the delivery slot 0" into the tube a", the limbs being during the insertion pressed towards each other. As soon as the guide piece has been completely inserted, the limbs d" are allowed to spring outwards so that the slot edges of the tube enter between the projections m, n.

If the guide walls of the U-shaped member serving for guiding the paper strip are fixed to the edge portions of the outlet slot 0'', the outwardly bent end portions h of the limbs d" used in the first constructions, are omitted. If desired, the free ends of the limbs d, d" may be properly centred with regard to the inlet-slot b", either by the inwardly bent edge portions of the slot b" or by inwardly bent tongues 11' (Figs. 5 to 8) formed at the edges of the slot, or centering points pressed into the wall of the tube close to the edge portions of the slot. engaging between the free ends of the guide walls. It is. however,

not necessary to provide these centering or regs istering devices as the U-shaped guide member is sufiiciently held in position by being fixed to the edge portions of the delivery slot 0.

The walls which guide the paper strip may, in addition to their engagement with. the outlet slot c', have also engagement with the inlet slot b'" as shown in Fig. 14. In-that case it is possible to fix the guide walls to the edge portions'of both slots 01' the tube of the spool. For instance, as shown in Fig. 14, the limbs d', d' of the guide member may be provided close to the apex'portion f" with outer projections or bulges m, which engage the longitudinal edge portions oi the outletv slot 0" whilst the ends 11. projecting through the inlet slot are bent outwardly around the edges V of the inlet slot.

Various modifications are possible within the.

scopeoi the invention, more particularly various ways of fixing the guide-walls. For instance, the

construction-shown in Fig. 14 may be modified so that the U-shaped guide memberd', d', f'"

is secured with its apex portion to the edges of the. inlet slot b in the same manner as shown in Fig. 14 with reference to'the outlet slot .c'f' and merely engages with its free ends the outlet slot c'".

Moreover, the member 11'", d"f, f'" mightbe held 'bytongues or projections stamped out of the side of .the tube, said tongues or projections engaging recesses of the limbs d, d

I claim:

1. A'photographic roll film spool comprising in combination: a tube made of sheet material and having van inlet. slot and an outlet slot for the passage of a paper strip carrying the film; a

member of substantially U-shaped cross section made 01 sheet material inserted into said tube and gripping with its apex portion the outlet slot of said tube, said member forming guide walls for the paper strip; outwardly bent ends on the limbs of said member resting upon the portion of the tube containing the inlet slot;

said guide walls being shorter than the tube; and

, passage of a paper strip carrying the film; a member of substantially U-shaped cross section the limbs of said U-shaped member being recessed adjacent to the apex portion for the purpose of providing stops limiting the engagement of the apex portion with the outlet slot.

2. A photographic roll film spool comprising in combination: a tube made of sheet material and having an inlet slot and an outlet slot for the made of sheet material inserted into said. tube and having transverse edge portions. engaging the transverse edge portions of the outlet slot,-

and end portions on its limbs bent to engage frombelow the longitudinal edges of the outlet slot, whereby said member is held in place; said member forming guide'walls for thepaper strip which are shorter than the tube. 3. A photographic roll film spool comprisin in combination: a tube made of sheet material and having an inlet slot and an outlet slotfor the passage of a paper strip'carrying the-film;

a member of substantially U-shaped cross sec tion made of sheet material inserted into said tube and having transverse edgeportions 'engaging the transverse edge portions of the outlet slot, and end portions on its limbs bent to engage from below the longitudinal edges of the having an inlet slot and an outlet slot for the passage of a. paper strip carrying the film; a member 01 substantially U-shaped cross section made of sheet material inserted into said tube and comprising tongues formed on the transverse edges of its apex portion and engaging the transverse edges 01 the outlet slot; said member forming guide walls for the paper strip which are shorter than the tube.

5. A photographic roll film spool comprising in combination: a tube made of sheet material and having an inlet slot and an outlet slot for the passage of a paper strip carrying the film; a

member oi substantially U-shaped cross section made 01' sheet material inserted into said tube and having transverse edge portions engaging the transverse edge portions of the outlet slot, and end portions on its limbs bent to engage from below the longitudinal edges of the outlet slot,

whereby said member is held in place; said mem ber forming guide walls for the paper strip. which are shorter than the tube; and said inlet slot comprising small inwardly bent tongues formed on its edges and serving to fix the tree ends of the limbs of said guide member relatively to the inlet slot. i r

6. A photographic roll film spool comprising in combination: a tube made of sheet material and having an inlet slot and an outlet slot for the passage oi a paper strip carrying the film;

- guide walls made of sheet material inserted into said tube and fixed to the edge portions of the outlet slot for guiding said paper strip, said guide walls being shorter than the tube; and said guide walls being provided at their ends adjacent to the outlet slot with two outwardly extending projections or bulges which engage from above the edges of the outlet slot of said tube and thereby hold said guide walls in position in the tube.

7. A photographic roll film spool comprising in combination: a tube made of-sheet material and having an inlet slot and an outlet slot for the passage of a paper strip carrying the film; a member of substantially U-shaped cross section made of sheet materiaiinserted into said tube and having convergent limbs which form guide walls for the paper strip and enter and grip at the apex portion of said member the outlet slot of saidtube, said guide walls not being substantially longer than the outlet slot.

8. A photographic roll film 'spool comprising in'combination; a tube made of sheet material and 'having an inlet slot and an outlet slot for the passage of a paper strip carrying the film; a member of substantially U-shaped cross section made ofsheet material inserted into said tube and having convergent limbs which form guide walls for the paper strip and enter and grip at the apex portion of said member the outlet slot of said tube, said guide walls not being substantially longer than the outlet slot; and outwardly bent ends on. the limbs of said member resting upon the portion of the tube containing the inlet slot. a

9. A photographic roll film spool comprising in combination: a tube made of sheet material having aninlet slot and an outlet slot for the passage of a paper strip carrying the film; guide walls made of sheet material inserted into said tube and entering and gripping at their two ends the inlet and outlet slots respectively, said guide walls not being substantially longer than the outlet slot.

10. A photographic roll film spool comprising in combination: a tube made of sheet material having an inlet slot and an outlet slot for the passage 01 a paper strip carrying the film; a member or substantially U-shaped cross section made of sheet material inserted into said tube and having convergent limbs which form guide walls tor the paper strip and enter and] grip at tively, said guide walls not being substantially longer than the outlet slot and being fixed to the edge portions of the inlet and outlet slots of the tube.

PHIL'EPP SCHWARZ. 

